Functional safety represents a clear differentiator for current and future products in automotive industries and in particular with sensor systems. To achieve corresponding targets in terms of automotive safety integrity level (ASIL), new and enhanced concepts have to be established. To achieve a dedicated ASIL level, different target parameters such as a failure in time (FIT) rate, diagnostic coverage, single point fault metric (SPFM), latent point failure metric (LPFM), or other system parameters have to achieve a dedicated value. For sensors, a typical safety goal is it to ensure dedicated signal accuracy in a predefined time (e.g., 5° deviation of the true angle value has to be detected in 5 ms at an angle sensor). The problem to be overcome in that context is simply how to prove a dedicated diagnostic coverage by specific safety mechanisms. The choice of safety mechanisms represents an important element and the more a dedicated mechanism is able to cover, the better and more fail-safe the system.
An important element represents the interface between sensor and the controller or other component, as this can only be covered partly by internal checks as well as partly by external checks. Therefore innovative concepts for the interface are needed to cover the link between sensor and system control units in an optimal, efficient and costly form.